My desktop cut out and won't turn back on.

patashnik

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Mar 30, 2013
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I use an older desktop with spare kit as a server box for TeamSpeak, etc. It also mines bitcoins almost 24/7, and has done so for months without issue. Yesterday it cut out suddenly, like from overheating, and while it was a little sunnier, it's still a Scottish spring and the room was at a comfortable temp. It also has new and functioning fans rear and side, a CPU heatsink, and the GPU has a good few inches top and bottom, so it's well aired and uncrowded.

Regardless, I left it for a few minutes to cool off before trying to turn it back on, but nothing happened. The mobo has a power LED so I believe it and the PSU are working to some extent. I did notice one of the HDDs wasn't secured properly and was resting on some cables tucked below the drive rack, but it might've been touching the metal bottom of the case - a long shot, but could this have caused a short-out?

I don't think any of the components are more than three years old. I removed the GPU and RAM sticks and then stuck them back in, and have disconnected the HDDs and all the cables out the back except for the power, but still nothing. I checked mobo connections too, so I'm officially stumped. Google came up mostly with problems with OS failure, getting stuck at the BIOS, but I'm talking about the power button having no effect, not even jump-starting.

I hope this is enough (but not too much!) info, and thanks in advance.

Edit: the PSU is 750W, if that's relevant.
 
Solution
Hmmm, that suggests your PSU died. The +5VSB circuit is actually a separate little PSU inside the main one, so it could remain alive (powering your mobo "pilot light") even if the main one had died. While I'm not familiar with the CIT brand, the prices I found online for it suggest it is probably severely overrated. Replace it with a quality 500W unit and hope the CIT didn't take anything with it into the Abyss when it died.

patashnik

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The PSU is a CIT, but I can't find or remember the particular model. "P/N: EP10N1" is on the sticker, though.

MSI 790FX-GD70 mobo
AMD Phenom II X4 955 @ 3.20 GHz
4GB DDR3 RAM (generic)
Radeon HD 6870 1GB GDDR5

There's an older Hitachi 80GB HDD, and a WD Caviar Blue 250GB.

The result is the same having removed the CPU cable.
 
Hmmm, that suggests your PSU died. The +5VSB circuit is actually a separate little PSU inside the main one, so it could remain alive (powering your mobo "pilot light") even if the main one had died. While I'm not familiar with the CIT brand, the prices I found online for it suggest it is probably severely overrated. Replace it with a quality 500W unit and hope the CIT didn't take anything with it into the Abyss when it died.
 
Solution

patashnik

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I did get the PSU cheaply years ago and so am not too surprised to hear this. I've read about the "sub-PSU", so that explains the light, like you said. I'll invest in something more robust and check in once I've installed it. Thank you for the swift response.
 
A quality 500W unit would be an appropriate size. Seasonic, Antec, FSP, and Enermax/LEPA have good budget models. I'm not fond of the Corsair "Builder" line because they're made by CWT, not Seasonic, using some inferior Samxon capacitors known for early failure; even that would be a much better choice than many of the alternatives, although I'm sure bitmining keeps the temps in your case up. Those cheap capacitors don't like heat.


 

patashnik

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That's a shame - I didn't check back soon enough and have since ordered a Corsair CX750. I'll actually put it in my main rig and use its OCZ (600W) for the spare box. I should be able to cancel the order so I'll think it over - I'd like to keep mining without worrying about something crapping out.
 
Well, check the load at the wall. If you're well under the PSU's capacity, you won't be putting a lot of stress on it, so it shouldn't heat up too much. Then make sure your case fans are balanced (not all exhausts), so the PSU doesn't have to fight your case fans to keep air moving through it.
 

patashnik

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I've cancelled the Corsair and ordered a Seasonic in its place - same price at a loss of wattage, but I'll take your word about the minor fault there.

I've never checked power usage at the wall before. The server box's two fans are those 4-pin connectors, which means the speed is automatically adjusted, right? I installed them because I'd been using a single stock one with only a molex connector, and the noise was horrendous.

If you're interested re: power usage, these will be the two boxes' setups come the new PSU.

Asus Z77 Sabertooth
Intel Core i7-3770K CPU @ 3.50GHz
16GB DDR3 RAM
NVIDIA GeForce GTX 670
2TB + 500GB HDD
Seasonic S12II-520 (520W)

MSI 790FX-GD70
AMD Phenom II X4 955 CPU @ 3.20 GHz
4GB DDR3 RAM
ATI Radeon HD 6870 1GB GDDR5
80GB + 250GB HDD
some OCZ @ 600W